Cross-lap suturing technique: a new strategy for repair of chronic perineal lacerations.

INTRODUCTION: Chronic obstetric anal sphincter injuries (OASIS), particularly grade IIIb and IV perineal lacerations, often cause persistent fecal incontinence and severely impaired quality of life. Conventional overlapping sphincteroplasty is limited for chronic injuries due to muscle atrophy, fibrosis, high local tension and insufficient soft tissue coverage. This study presents a modified cross-suturing technique (Cross-lap) to optimize sphincter reconstruction and lower adverse tension distribution. METHODS: Developed based on anatomical reconstruction principles, the Cross-lap technique is indicated for chronic or neglected OASIS. Its core step cross-folds external anal sphincter stumps and fixes them contralaterally in the dissected rectovaginal septal space. We describe its key surgical maneuvers, technical key points and preliminary clinical outcomes via a single illustrative case: a 58-year-old postmenopausal woman with chronic grade IV perineal laceration. RESULTS: The Cross-lap suturing technique reconstructs the complete anal sphincter complex while decreasing bulky overlapping muscle tissue. Short-term follow-up of this illustrative case showed relieved fecal leakage, perianal dampness, anal fullness and impaired daily activity, alongside improved defecatory control. No severe early postoperative complications occurred, confirming its technical feasibility. Future large-cohort studies will adopt the validated Wexner score to objectively quantify functional recovery. DISCUSSION: As a refined alternative to standard sphincteroplasty, this method redirects sphincter contractile force cephalad and mitigates stress concentration at the repair site. Such biomechanical benefits make it suitable for chronic OASIS patients with scarred, atrophic or fragile perineal tissues. Larger cohorts and extended follow-up are needed to verify its long-term clinical efficacy.